Dynegy Sparks Some Interest in Power Producers

Why bother owning power stations if you can't give the odd jolt now and again?

Dynegy's announcement on Friday of $6.25 billion worth of acquisitions sent its stock up 23% at one point. That later slipped to single digits; still respectable, but perhaps reflecting that the sector relies increasingly on self-help.

Because natural-gas prices set power prices in much of the U.S., merchant power plants are often leveraged bets on...